1. Field of Invention
The present invention relates to systems for conveying engine exhaust gases from an automobile engine located in an enclosed work space and discharging the gases into the atmosphere outside the enclosed work space. More particularly, the invention relates to systems in which a length of flexible tubing is connected at its inner end to an engine exhaust pipe to convey exhaust gases to its outer or downstream end from where the gas is discharged to outside atmosphere.
2. Description of Related Art
When automotive vehicle engines are operated at various types of servicing facilities such as garages, repair shops, automotive dealerships etc., potentially harmful combustion products are produced and discharged through one or more vehicle exhaust pipes. Since the engine being serviced is usually located in an enclosed work space, these gases must be removed by conveying them out of the work area and discharging them into the atmosphere outside the enclosed work space.
Some systems employ a network of conduits either buried in the concrete floor of the service facility or suspended overhead. The engine exhaust pipe or pipes are connected to these conduits through lengths of flexible tubing. In other arrangements, the engine exhaust is conveyed through a separate conduit in the form of a length of flexible tubing that extends through a wall or door panel so as to discharge the gases to outside atmosphere. Flexible tubing that is suitable for such purposes is disclosed in U.S. Pat. Nos. 2,832,096; 4,308,228; 5,435,962: and 6,102,078, for example. This type of flexible tubing is crush resistant and is formed of elastomeric material that is initially in an uncured condition. When the uncured product is formed and cured, it provides a strong but flexible length of tubing with helical corrugations along its length.
Briefly, the method for making the tubing comprises sliding an extruded sleeve of uncured rubber axially over a rotatable mandrel, the mandrel having a continuous thread formed on its outer surface. When in place on the mandrel, the sleeve is forced into the helical groove or root of the thread by a length of cord wrapped around the sleeve as the sleeve rotates with the mandrel. This serves to impart a desired corrugated shape to the uncured rubber sleeve. The resulting assembly is then removed from its support and placed in an oven or autoclave to cure the rubber and set the helical corrugations. The cord is then removed from the tubing and the tubing is removed from the mandrel. The overall method thus described is generally known as the “cording” process.
In order to connect the inner end of the flexible tubing to the vehicle exhaust pipe or pipes, the length of flexible tubing generally has an adapter or boot secured to its inner end. Adapters or boots for this purpose are disclosed, for example, in U.S. Pat. Nos. 2,754,138; 2,789,841; and 4,804,019. Generally the adapter or boot is flared outwardly to define an enlarged opening. This permits the boot to be slid over the end of the exhaust pipe in a fairly loose fitting condition. Then the boot is tightened around the exhaust pipe using, for example, one of the techniques shown in the above U.S. Pat. Nos. 2,754,138; 2789,841; and 4,804,019.
To provide further assurance that the boot will remain on the exhaust pipe, a chain with a hook at one end is often connected between the boot and a connection point located in the undercarriage of the vehicle. The chain is connected so as to urge the boot into secure engagement with the exhaust pipe.
A new development, however, has made the positioning of the boot in alignment with the exhaust pipe more difficult. More particularly, some newer motor vehicle designs, instead of having the exhaust pipe under the rear bumper, now have the exhaust pipe positioned in an opening in the bumper or other rear panel, well above the bottom of the bumper. In some cases the end of the exhaust pipe is flush with the surface of the bumper. With this new exhaust pipe discharge location, the standard practice of sliding the boot over the end of the exhaust pipe and connecting a hook and chain from the boot to the undercarriage of the vehicle is not workable. Thus a need exists for an alternative approach to positioning the boot in alignment with the exhaust pipe.
The apparatus and method of the present invention satisfy the need described above and afford other features and advantages heretofore not obtainable.